With age a large percentage of the population develops arterial obstructions formed by fats, fibrous material and calcified deposits, resulting in a diminished blood circulation. The disturbance to blood flow which these obstructions cause may induce blood clots which further diminish or block the blood flow. When this process occurs in the coronary arteries it is referred to as a heart attack. Presently such obstructions are circumvented by surgically grafting a bypass or they are treated by a catheter equipped with a balloon which is inserted through the arterial system, over a flexible guide-wire, into the obstruction and then inflated to expand the obstruction's lumen (angioplasty). Problems with this treatment are that it injures the arterial wall creating a rough lumen and in certain cases it is ineffective. Further, angioplasty does not remove the obstruction material out of the arterial system, therefore in a case of a heart attack, immediate angioplasty carries the risk of dislodging the blood clot and allowing it to move down stream creating additional blockages.
An objective of the invention is to provide an atherectomy catheter rotatable over a flexible guide-wire, equipped with a rotary cutting means at its distal end, that would cut and ingest the obstruction material, including blood clots if present, create a smooth lumen and not crack the arterial wall.
A further objective of the present invention is to provide suction means to assist the flexible rotary-catheter in ingesting the obstruction material. Preferably, a self regulating suction means that automatically increases and decreases the suction in response to the presence or the absence, respectively, of obstruction material in the flexible rotary-catheter. Thereby, such suction means reduces the amount of blood removed from the patient.
Another objective of the invention is to provide a system that would lend itself to be produceable in diameters down to around 1 mm (millimeter) and a length of up to around a meter, to be able to reach and enter small and remote arteries.
Preferably, the operation of the atherectomy system would resemble the operation of present catheter systems, so that existing skills of the medical staff can be utilized. These and other objectives of the invention will become apparent from the following discussion and the accompanying drawings.